Clever Luna Moths Use Decoys to Fool Bats

Fluttering “tails” can foil an attack.

Light green, long winged, and roughly the size of a playing card, the luna moth is a striking creature. It’s a clever one too, say biologists Jesse Barber and Akito Kawahara, who have found that the “tails” at the ends of Actias luna’swings are more than just cool-looking appendages. They’re actually expendable decoys that trick hungry bats.

As the echolocating hunter comes in for the kill, says Barber, the moth’s moving tails distract and fool the bat, knocking its attack off target; it may nab a bite of an extremity but seldom the whole insect.

“Moths and bats have been engaged in acoustic warfare for 60 million years,” say Barber and Kawahara. This work expands scientists’ knowledge of “antipredator deflection strategies,” they say—and of how moths adapt to compete in this “evolutionary arms race.”